The WijExpander control allows you to show or hide embedded or external content within an expanding panel using various animation effects. The expanding content can be shown or hidden by clicking on the expander header at run time.
WijExpander Markup
The following markup creates a WijExpander control. Set the TargetControlID property to attach the extender to a control.
<cc1:WijExpander ID="Panel1_WijExpander" runat="server" TargetControlID="Panel1"></cc1:WijExpander>